Air Duct Replacement in Simi Valley, CA

When does duct replacement beat another cleaning?

The test is the inner liner. Pull a register and look up the branch. If the flex liner has torn loose at the collar, cleaning does nothing. Air is then moving through raw insulation and the attic cavity. Same answer for crushed runs flattened over joists, and for any duct carrying rodent or bird nesting debris. Those come out. They do not get scrubbed.

Most Simi Valley tract homes from the 1970s forward use an attic horizontal furnace and coil, with flex branches to ceiling registers. Decades of attic heat cycling stiffen that liner and shrink the mastic at collars. Replacement means new flex, new sheet metal collars, mastic and mechanical strapping at every joint, and strap spacing that keeps runs off the joists.

Replacement is also the time to fix the return. One undersized central return is the standard complaint here. It pulls wall-cavity dust past a loose filter rack. Adding return area, or sealing and insulating the return plenum, stops the marine-layer sweating that feeds mold near the drain pan.

What moves a replacement quote is run count, attic clearance over low-pitch roofs, and whether the trunk and plenum are reused or rebuilt. Count your ceiling registers first.